First an assumption: You are new to guns/rifles or haven't done much other than shoot them and clean them.
Apologies if I'm wrong.
Ok first thing to do is to go out to
Fulton Armory . On the left side of the page is a site index. Find the section for the M1 Garand and you'll see links to a lot of info, as well as parts for the gun. This is probably the best place to go for high quality parts.
I'd also have a gunsmith look at it and make sure that it's in good condition ie. Op-Rod is straight, chamber is within spec, gas cylinder is still good etc.
The chances are low that this would have any collector value, but research might tell you. That could affect what you do to the gun.
These are absolutely fantastic guns, so be carefull what you decide to do to it. I do a lot of my own work on my guns, but some things are best done by the pros. I'd be particular about who I gave the gun to for Parkerizing if it really needs it in the first place.
I have the civilian version of the M14, which came later. I bought it for high-power rifle competition, which the M1 isn't as good for, but I still have to have one someday. I've shot them plenty of times and they are sweet!
Watch out for the M1 thumb!!!
